ABSTRACT: Blanke et al. reported in Nature magazine
how stimulating the right angular gyrus in a patient
with a right temporal seizure focus with a 4mA or 5mA
current, produced transitory out-of-body experiences
(OBEs) involving seeing either legs or arms disappearing
when she attempted to “inspect the illusory body
or body part.” Despite their reporting that changes
in visual attention and/or current amplitude in the
angular gyrus could explain the
“phenomenological modification”, this finding
produced significant press interest, as a site for the
OBE was postulated. This brief paper puts this and similar
findings into perspective.

1. The OBE described appears atypical for
the type of subjective OBE described by Subjective
Paranormal Experients (SPEs).
2. The likely pathological angular gyrus in this patient
cannot be compared with that area in normal individuals.
3. Generalisation of this one case to other humans
is not warranted.
4. Additionally, a previous second case suggests more
than one locality for provoking an OBE by electrocortical
stimulation. When analysing comparable phenomena such
as déjà vu and memory, no single localisation
can be found.
5. Even when findings on subjective paranormal experiences
(SPEs) including OBEs are referable to specific anomalous
brain functioning, they neither confirm nor deny the
veridicality of the SPEs. These may have endogenous
origins within the brain like pathological hallucinations
do; or a particular brain function pattern may allow
experience of an outside, usually covert, reality.
6. At least four distinct nosological subtypes of
déjà vu exist. Similar research on OBEs
needs to be performed to demonstrate the likely subtypes
that exist.
Methodologically, associative links do not imply causality.
To consolidate the causality hypothesis, one should
analyse SPEs and also the converse, like temporal
lobe epileptic subjects. The reductionistic fallacy
of OBEs being fully explained purely on the basis
of stimulating a specific area of the brain is not
tenable.

INTRODUCTION

On 19th September 2002, the prestigious
journal, Nature, published a brief communication. (Blanke,
Ortigue, Landis, & Seeck, 2002). Although the conclusions
of the Swiss authors were conservative and preliminary,
the title of the article made a radical claim: Stimulating
illusory own-body perceptions: The part of the brain
that can induce out-of-body experiences has been located.

Within days this was picked up by numerous internet
groups and a variety of news agencies applying sensational
titles:

Time
magazine
Hit The O-Spot For Out-of-Body. Had an out-of-body experience?
Scientists believe they know why: “Shamans teach
that out-of-body experiences are best achieved through
meditation, reflection and transcendental calm. Scientists
believe they have found a less celestial source: the right
angular gyrus of the brain.”

These are examples
of what the media has made into major conclusions about
an article that I perceive as a preliminary contribution
at best. These vast “scientific” jumps require
careful review as they claim radical new knowledge of
the brain and the paranormal. Having myself worked a
great deal with analyzing the phenomenology of déjà
vu, olfactory hallucinations, subjective paranormal
experiences and temporal lobe symptomatology, and having
gone to great pains to indicate the dichotomous nature
of brain-related explanations for such events (endogenous
within the brain; or a brain patterning allowing for
the appreciation of exogenous experience), I find such
sensationalism premature.
This brief paper is an attempt at putting this and similar
findings into perspective. I cover the following areas:

The authors, Blanke et al. (2002), use the definition:
“Out-of-body experiences (OBEs) are curious, usually
brief sensations in which a person’s consciousness
seems to become detached from the body and take up a
remote viewing position” (Grusser & Landis,
1991; Hecaen & Ajuriaguerra, 1952).
Whereas this definition is adequate and the patient
they describe fits this definition, I believe it is
critical to define the OBE as a form of “subjective”
experience. This allows interpretations that are as
subjective as research on “hallucinations”,
“flashbacks” and “déjà
vu”. For this reason, I developed the term “Subjective
Paranormal (Psi) Experience” (SPEs: Neppe, 1980)
to emphasise the fact that such experiences need not
be objectively demonstrated in the lab, but that criteria
could be used to separate out “Subjective Paranormal
(SP) experients” from “non-experients”
and that patients with normal or abnormal brain functioning
could be analysed for such experiences, just as they
are for hallucinations or delusions, which are other
kinds of subjective experiences.

A procedural perspective

The team of researchers at the University Hospitals
of Geneva and Lausanne (Olaf Blanke, Stephanie Ortiguet,
Theodor Landis, Margitta Seeck from the Laboratory of
Presurgical Epilepsy Evaluation, Program of Functional
Neurology and Neurosurgery) stimulated areas of the
brain under local anesthesia to determine exact localisations
of brain function and seizure firing as a presumed precursor
for performing epilepsy surgery. This procedure is common,
routine under this circumstance, and done worldwide.
The research findings were based on just a single patient,
which usually implies at most a Journal Letter, not
a Brief Communication in a prestigious journal, as in
this instance. The 43-year-old female right-handed patient
had suspected right temporal lobe epilepsy: Stimulating
her right side of the brain would almost certainly stimulate
the non-dominant hemisphere.
The researchers demonstrated the epileptic focus two
inches anterior to the stimulation site of relevance,
the right angular gyrus, a little discussed area based
in the parietal lobe, but with links to the temporal
lobe. The stimulation area did not evoke part of the
patient’s habitual seizures.

The actual symptoms described

Initial stimulations (n = 3; 2.0, 3.0 mA) induced subjective
“sinking into the bed” or “falling
from a height”. Increasing the current amplitude
(3.5 mA) led to “I see myself lying in bed, from
above, but I only see my legs and lower trunk”
plus an instantaneous feeling of “lightness”
and “floating” about two metres above the
bed, close to the ceiling (by definition, an OBE).
At 4.5 mA, lying down with upper body supported at an
angle of 45 degrees legs outstretched, the patient reported
seeing her legs “becoming shorter”. With
the legs bent before the stimulation (90 degree knee
angle; n = 2; 4.0, 5.0 mA), she reported that her legs
appeared to be moving quickly towards her face, and
took evasive action.
When looking at her outstretched arms (n = 2; 4.5, 5.0
mA), the patient felt as though her left arm was shortened;
but the right arm was unaffected. If both arms were
in the same position but bent by 90 degrees at the elbow,
she felt that her left lower arm and hand were moving
towards her face (n = 2; 4.5, 5.0 mA). When her eyes
were shut, she felt that her upper body was moving towards
her legs, which were stable (n = 2; 4.0, 5.0 mA).
The researchers concluded that these observations indicate
that “OBEs and complex somatosensory illusions
can be artificially induced by electrical stimulation
of the cortex,” and that their

“anatomical selectivity suggest that they
have a common origin in body-related processing, supported
by the restriction of these visual experiences to the
patient’s own body. During her OBE, the patient
only ‘saw’ that part of her body that she
also felt was modified during her body-transformation
experiences.”
(Blanke et el., 2002)

Further, the “out-of-body and body-transformation
experiences were transitory,” disappearing when
she attempted to “inspect the illusory body or
body part.”

In my opinion, these descriptions appear atypical
for the SPE OBE that is seen in SP Experients. When
they are elevated above the body, they see not only
their own body but the surroundings, and reports of
body distortions do not play a role. Moreover, they
are generally not transitory in that they are maintained
if the subject attempts an “examination.”
The actual conclusions made in the Blanke et al. paper

The authors (viz., Blanke et al., 2002) suggest that
changes in visual attention and/or current amplitude
in the angular gyrus could bring about these phenomenological
modifications. The authors therefore, in any event,
give an alternative explanation in terms of “visual
attention” changes to the angular gyrus hypothesis.
It is the media above, that have ignored the visual
attention hypothesis and focussed purely on the OBE
and the angular gyrus. The term “phenomenological
modification” is used by the authors, not OBE
in this context.

The angular gyrus and localization of OBEs

The right angular gyrus has been known to co-ordinate
spatial relations (Baciu et al., 1999), and may modulate
both shifts of attention within extrapersonal space
and saccadic eye movements (Vuilleumier, Hester, Assal,
& Regli, 1996). It may be involved in learning target
positions (Kawashima, Roland, & O’Sullivan,
1995). The authors believe that based on previous neurological
investigations of body-cognition disorders, the angular
gyrus could be a crucial node in a larger neural circuit
that mediates complex own-body perception (Blanke et
al., 2002). Thus there is a theoretical link with spatial
movements, and the “OBE” described may fit
this framework.
However, the Blanke et al. report is just one case.
A second, older case, apparently contradicts the anatomical
angular gyrus finding:

“The stimulating current was shut off and the
electro-corticogram showed that a slow wave four per
second generalized rhythm had been set up as an after-discharge.
While this was continuing the patient exclaimed: ‘Oh
God! I am leaving my body!’ Dr. Karagulla, who
was observing him, said he looked terrified at the time
of the exclamation and made gestures as though he sought
help.” (Penfield, 1955, pp. 451-465; see also
Penfield, 1958)

Penfield’s temporal lobe epileptic patient subjectively
felt he was having an out-of-body experience.
Thus the two cases in the literature may suggest evidence
for non-localisation or more than one locality for provoking
an OBE by electrocortical stimulation.

Penfield’s (1955) patient was prone to attacks
of déjà vu preceding his major epileptic
manifestations. Given this, is déjà vu
localised in the brain? Based on stimulatory work in
the brain, we know that déjà vu does not
apparently have one specific, consistent localisation.
Halgren, Walter, Cherlow, and Crandall (1978) evoked
déjà vu by stimulating the hippocampus
and hippocampal gyrus. This was unexpected, as previous
déjà experience had not been evoked from
the mesial temporal areas. Halgren’s work involved
3,495 stimulations of 36 psychomotor epileptics, wherein
267 mental experiences were evoked. Of the 19 déjà
experiences evoked, 18 occurred in patients who had
previously had déjà vu as part of their
aura. (Compare this with the single case in the Blanke
et al. study!) Thus déjà vu is non-localisable
or at least has more than one stimulatory origin (Neppe,
1981, 1983b, 1983c). As another example of non-localisability,
memory in the brain involves several discrete and combined
functions and cannot be located easily (Neppe, 1983c;
Oyachi & Ohtsuka, 1995).
Consequently, even if purely endogenous, there could
be limited localisation for OBEs as well.

Comparisons: Different subcategories of
déjà vu

Neppe (1983a, 1983b) analysed déjà vu
in different subtypes in great detail. He demonstrated
that there are at least four phenomenologically distinct
subtypes of déjà vu (N = 89). These corresponded
to diagnostic categories, and such phenomenological
experiences may be used in diagnosis and management
and can explain the wide variety of déjà
clinical manifestations. Temporal lobe epilepsy déjà
vu occurs in some temporal lobe epileptics; associative
déjà vu in so-called “normals”;
déjà vu in schizophrenics reflects a further
nosological category; and finally a subjective paranormal
experience (SPE) déjà vu is characterised
by specific anomalous time distortions in SP experients
(Neppe, 1983b, 1983c).
Thus not only is déjà vu not easily localised,
one can distinguish subtypes that likely have entirely
different aetiologies (Neppe, 1982). This has not been
done yet in OBEs and this research needs to be performed
to make specific nosological conclusions.

Neppe also looked at other kinds of SPEs. He demonstrated
that olfactory hallucinations of a specific kind occur
in SP Experients and that again there is additionally
a phenomenological link with the temporal lobe (Neppe,
1982, 1983a). He extended this work demonstrating more
possible temporal lobe symptoms (PTLSs) are associated
with ostensibly normal subjects claiming a large number
of SPEs (experients) than with non-experients; and this
was at both state and trait level. These findings suggest
an anomalous kind of temporal lobe functioning among
the experients, but neither confirm nor deny the veridicality
of their SPEs (Neppe, 1979, 1983d). Like pathological
hallucinations, the SPEs may have endogenous origins
within the brain; alternatively, a particular brain
function pattern may allow experience of an outside,
usually covert, reality.
Palmer, Neppe, Nebel, and Magill (2001) have recently
extended this work to the converse, namely analysing
the SPEs of temporal lobe diseased patients. This way
they are attempting to establish causal links as opposed
to associative links. This kind of work has not been
done in OBEs and needs to prior to major conclusions.

The phenomenological categorisation of
the out of body experience

Looking at the detail required to categorise different
phenomena (Neppe, 1981, used 55 different sub-parameters
for déjà vu, and multidimensional scaling
using median column geometry in 22 different dimensions),
it is logical to hypothesise that there may be different
subcategories of OBE. These need to be analysed in detail
and we could potentially demonstrate various subtypes
in this way. For example, temporoparietal OBE may have
as its features patients with non-dominant complex partial
seizures and cerebral cortical spatial pathology who
experience their OBE usually by brain stimulation and
involve not spontaneously seeing all the body plus all
the environment, but specific anatomical areas which
can be modulated by speech, movement and outside stimuli.

The reductionistic fallacy

The reductionistic fallacy is common in science, medical
science and psychology. It implies implicit “nothing
but” in front of some physical relation, with
an assumed purely physical hierarchy of sciences. Psychologically,
we frequently learn we are nothing but stimulus-response
and maybe organism, and that everything can be explained
in our brains, genes and bodies. This is currently the
default worldview of most scientists.
In this instance, the media particularly has jumped
onto a cautious and preliminary statement by authors,
and implied that OBEs can be fully explained purely
on the basis of stimulating a specific area of the brain.
There is no relevance to the specific, special condition
of the patient who has temporal lobe seizures. Surely
this is not the only patient whose angular gyrus has
been stimulated? Yet, there is no mention of the other
patients who also have partial (focal) epilepsy, whose
brains this same research team stimulates, and who have
not presumably described OBEs (otherwise surely we would
be learning of the second and third cases as well.)
Furthermore, we know nothing of the parapsychological
background of this patient. Does she have subjective
paranormal experiences? Has she had previous spontaneous
OBEs? If so, have they been qualitatively the same as
the current one described? Have some of the SPEs occurred
at the same time as her temporal lobe symptoms—are
they state related? Have some occurred separately (i.e.,
she has a trait potentially linked with a pattern of
brain function)? What role did the environment play?
The stimulation of her brain under local anaesthesia
occurred with surgeons interacting in bringing forth
her description of being “out of body,”
a term not, incidentally, used by the patient. In this
instance, she was seeing separately two limited parts
of her body—legs and, on command, arms. How different
is this from the so-called phantom limb phenomenon,
where patients “feel” an amputated limb?
These may seem petty points but they are not. Tiny psychological
and physical features need to be recorded because they
become variables that are uncontrolled in a single case
history. Psi research has always paid enormous attention
to detail, understanding the great confounding factors
that could occur if not everything is properly controlled.
Certainly, generalisation of this one case to other
humans is not warranted.

Legitimate conclusions—multiple possibilities

Where are we now after the Blanke et al. (2002) paper?
Simply, with a second reported case of stimulating an
area of the brain and producing a specific qualitative
out-of-body experience as a consequence. We can say
the following:

1. The OBE described by Blanke et al. (2002) is significantly
atypical compared with those typically reported in
subjective paranormal experients, who see not only
themselves but an extended environment. Furthermore,
there may also be another phenomenologically distinct
category of OBE in near-death experiencers, as well,
who may recall events even while in coma—something
very unphysiological indeed (Morse & Neppe, 1991).
Thus the Blanke et al. OBE may just be one OBE variant
and any conclusions drawn cannot be generalisable
to all OBEs.

2. Even though the epileptic focus was two inches
away from the right angular gyrus and the stimulation
area did not evoke part of the patient’s habitual
seizures, the fact that the patient had complex partial
seizures implies that the angular gyrus cannot be
compared with that area in normal individuals, as
the brain may develop compensation mechanisms to stop
seizure spread, or may have silent areas of spread,
or may have changed sensitivity having been provoked
over years by seizures and even presumably anticonvulsant
medications. Thus areas a little distant from the
focus cannot legitimately be regarded as the same
as they would be in normal patients without seizures.
Even given a large cohort of epileptic patients, not
a single case history, these results cannot be generalised
to normal subjects. And, as we cannot ethically stimulate
“normals,” we will not be able to generalize
this by future research.

3. We have recognised the need for normal and neuropsychiatric
subjects in our research on the temporal lobe and
SPEs (Palmer et al., 2001), so that better causal
links as opposed to strong statistical supportive
associative links can occur. The first work looked
at “psychics” functioning normally (Neppe,
1984) prior to embarking on neuropsychiatric patients.
Until the same is done for OBEs, even tentative conclusions
may be premature. Certainly, a sample size of one
or two complicates interpretations! Evocation of OBEs
by multiple stimulations even in many subjects still
would not imply source. All it implies is a link—not
cause and effect.

4. The angular gyrus is unproven as a link with even
the specific phenomenological subtype of OBE described
as it is based on a single subject with demonstrable
seizure pathology two inches away. Using the parallel
of déjà vu and memory, out-of-body experiences
may not easily be localised as a source of interaction
within the brain.

5. Clearly, OBEs should occur somewhere in the brain.
It may be linked with the temporal lobe or the angular
gyrus or may involve multiple brain areas interacting.

6. Even though a certain pattern of brain function,
either as a trait or state condition, may allow the
experience of anomalous events, this would neither
confirm nor deny the veridicality of any kind of SPE,
including the OBE, as deriving either from outside
the brain, or endogenously—when the SPEs would
be artifactual dysfunctions in the brain akin to hallucinations.